Electric utilities and owners or operators of other types of infrastructure lines, such as rail lines, pipelines, and the like, typically use airplanes, helicopters, and ground-based vehicles to inspect and monitor those lines and their associated right-of-ways. Regular inspection of these items is necessary or helpful to detect and document problems; to identify and reduce equipment failures; to detect encroachments onto right-of-ways, theft, vandalism, and terrorism threats; to ensure safe operating conditions; and to plan and prioritize scheduled or emergency maintenance.
There are numerous drawbacks associated with existing methods. The use of conventional methods is costly and time-consuming. For example, the operating cost associated with helicopter monitoring may exceed $1,000 per hour. Manned aerial inspection may expose the inspectors and the public to danger, particularly because the inspection process often requires low-altitude flying to enable detailed inspections, and operating under those conditions can reduce safety margins. By contrast, inspection using ground-based vehicles, while somewhat safer, poses its own risks. Ground inspection requires a great deal of additional time for travel to inspection sites, and access to those sites may be limited or obstructed by forest growth, watercourses, or obstacles, particularly when a natural disaster has caused downed trees and other hazards.
Manned aerial inspection consumes significant amounts of fuel, which poses an emissions hazard in addition to the cost of fuel. It may additionally be difficult if not impossible to access tight locations to gather detailed views around and under towers, or around other structures such as buildings and bridges. Inspections must also be carefully planned to occur within the range of appropriate landing sites, so that inspecting some lines may require longer-range, more expensive vehicles.
Moreover, manned aerial inspection requires trained and licensed pilots, who must concentrate on tasks associated with flying, in addition to utility personnel who must ride alongside, to view the lines under inspection and to direct operations. These personnel are in addition to those typically required to review and evaluate video in order to discovery and document problems for follow-up.
All of the foregoing drawbacks tend to make frequent inspection of lines and right-of-ways cost-prohibitive, which leads to less consistent operation and in some cases operating conditions that are not as safe as possible. With access to more efficient mechanisms for conducting aerial monitoring, more frequent inspection and monitoring could be undertaken, which would in turn make regular and exceptional maintenance easier to complete and make operation more consistent and safer overall.